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Getting imu_data from jackal in simulation

asked 2017-03-26 20:48:34 -0500

rsmitha gravatar image

updated 2017-03-26 20:49:16 -0500


I am using the Jackal robot from Clearpath. I am running the jackal_gazebo simulation and trying to collect odometry and IMU data. I have written code which has the following:

  • publisher, to publish messages to "jackal_velocity_controller/cmd_vel" topic.

  • subscriber which subscribes to "jackal_velocity_controller/odom" topic for odometry data and uses a callback function to read from "nav_msgs"

  • subscriber which subscribes to "imu_data" topic for imu data and uses a callback to read from "sensors"

The publisher and subscribers connect to the same node. The odometry data is available and gets written into a file. The velocity commands are visible when I do: "rostopic echo /jackal_velocity_controller/cmd_vel" The imu data, however, is not coming through. The code has the jackal moving in a straight line with a linear velocity of 2.0 in the 'x' direction. The other values, including, angular are zeros.

I expected some IMU data to come through in simulation even if the given angular velocity was zero. Am I subscribing to the wrong topic? How can I get the imu data from the jackal in simulation?

Thanks and regards, rsmitha.

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answered 2017-03-27 20:37:05 -0500

The topic is imu/data not imu_data.

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answered 2017-04-04 02:21:00 -0500

rsmitha gravatar image

Hi tonybaltovski,

Thank you for the answer. You are right. There is another issue though which clearpath robotics has answered. The frame of reference for the jackal and the husky is such that the robot cannot travel in angular 'x' but can travel in angular 'z'. So in my example, I was giving angular velocity values to the 'x' component. That is one of the reasons why it was not working. The other is what you have mentioned.

Regards, rsmitha.

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Hi rsmitha, can you mark the question as answered? Angular X is the robot rolling which both the Husky and Jackal cannot do. They are able to drive forward which is linear x and rotate which is angular z. Try to avoid posting comments as answers.

tonybaltovski gravatar image tonybaltovski  ( 2017-04-04 06:13:06 -0500 )edit

Sorry, tonybaltovski. Have marked the question as answered.

rsmitha gravatar image rsmitha  ( 2017-04-04 06:35:44 -0500 )edit

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Asked: 2017-03-26 20:48:34 -0500

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Last updated: Apr 04 '17